Elemental Reductants for the Deoxydehydration of Glycols

The elements zinc, iron, manganese, and carbon are demonstrated to be practical reductants for the oxorhenium catalyzed deoxydehydration (DODH) of biomass model polyols. These reductants and their oxidization products remain heterogeneous throughout the reaction, which aids in their separation. Their effectiveness is shown with the catalysts ammonium perrhenate and trans-[(Py)4Re(O)2]+Z– (1). Stoichiometric experiments with the Re(V) complex indicate a likely rhenium 5↔7 oxidation cycle for the deoxydehydration of polyols reported herein.